(a) Field of the Invention
The present invention primarily relates to an application of encapsulation material and manufacturing processes of a light-emitting diode (LED), eliminating the need for heating in a furnace during encapsulation manufacturing process of the light-emitting diode, prompting rapid curing thereof, and thereby enhancing production efficiency.
(b) Description of the Prior Art
Referring to FIG. 1, which shows a manufacturing process of a traditional light-emitting diode (LED), whereby the manufacturing process is divided into the following steps:
1, Die Bonding: The light-emitting diode chip is placed and bonded onto a pre-punched first leadframe.
2, Soldering: A metal lead is made to connect the light-emitting diode chips and a second lead stand thereby allowing conductance therethrough, enabling the first leadframe, a second leadframe, and the light-emitting diode chips to form an electrical link thereof.
3, Encapsulation: Upon injecting a thick, viscous, fluid epoxy resin into a mold, place the light-emitting diode chips, the first leadframe and the second leadframe into the mold.
4, Baking: Upon encapsulation, place encapsulant material into a heating furnace and heat at a high temperature. After 3 to 8 hours the thick, viscous fluid high molecule weight resin will have hardened, thereby completing encapsulation.
5, Cutting, testing and packaging.
Third step and fourth step of the aforementioned manufacturing process are steps involved in conventional “encapsulation”. An epoxy resin is a principle component of encapsulating “high molecule weight resin” material, whereby the epoxy resin is used as the encapsulation material of the light-emitting diode, primarily because the epoxy resin has properties of high transparency, high heat resistance, high thermal conductivity, resistance to humidity, and resistance to corrosion, features wherewith conform to light-emitting diode requirements of applicable environment and functionality.
The most universal epoxy resin utilized as the encapsulation material for the light-emitting diode is a thermosetting epoxy resin, which, before curing, is in a form of a fluid, sticky viscous liquid or a semi-gelatinous colloid. Upon adding a curing agent, and after baking at a high temperature for 3 to 8 hours will harden, thereby forming a cross-linked, solid polymer.
Furthermore, because of an enormous discrepancy between thermal expansion coefficients of the epoxy resin and the LED chips, during process of curing, cooling and shrinkage of the epoxy resin, internal stress may occur between the epoxy resin and the LED chips, engendering cracking of the epoxy resin, fracturing of the LED chips, separation of adhesion, shifting or splitting of component connected Leadframes, etc.
From the aforementioned integral manufacturing process of the light-emitting diode, wherein an extremely long time is spent in encapsulation of the epoxy resin and heat baking, furthermore, component formulation is complicated, and thus results in an inability to increase speed of producing the light-emitting diode, resulting in inefficient production. Therefore, there is a need for perfecting the manufacturing process.